/* ===========================================================
 * JFreeChart : a free chart library for the Java(tm) platform
 * ===========================================================
 *
 * (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
 *
 * Project Info:  http://www.jfree.org/jfreechart/index.html
 *
 * This library is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
 * License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
 *
 * [Java is a trademark or registered trademark of Sun Microsystems, Inc.
 * in the United States and other countries.]
 *
 * --------------------
 * FlowArrangement.java
 * --------------------
 * (C) Copyright 2004-2008, by Object Refinery Limited.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   -;
 *
 * Changes:
 * --------
 * 22-Oct-2004 : Version 1 (DG);
 * 04-Feb-2005 : Implemented equals() and made serializable (DG);
 * 08-Feb-2005 : Updated for changes in RectangleConstraint (DG);
 *
 */

package net.droidsolutions.droidcharts.core.block;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

import net.droidsolutions.droidcharts.awt.Rectangle2D;
import net.droidsolutions.droidcharts.common.HorizontalAlignment;
import net.droidsolutions.droidcharts.common.Size2D;
import net.droidsolutions.droidcharts.common.VerticalAlignment;
import android.graphics.Canvas;

/**
 * Arranges blocks in a flow layout. This class is immutable.
 */
public class FlowArrangement implements Arrangement, Serializable {

	/** For serialization. */
	private static final long serialVersionUID = 4543632485478613800L;

	/** The horizontal alignment of blocks. */
	private HorizontalAlignment horizontalAlignment;

	/** The vertical alignment of blocks within each row. */
	private VerticalAlignment verticalAlignment;

	/** The horizontal gap between items within rows. */
	private double horizontalGap;

	/** The vertical gap between rows. */
	private double verticalGap;

	/**
	 * Creates a new instance.
	 */
	public FlowArrangement() {
		this(HorizontalAlignment.CENTER, VerticalAlignment.CENTER, 2.0, 2.0);
	}

	/**
	 * Creates a new instance.
	 * 
	 * @param hAlign
	 *            the horizontal alignment (currently ignored).
	 * @param vAlign
	 *            the vertical alignment (currently ignored).
	 * @param hGap
	 *            the horizontal gap.
	 * @param vGap
	 *            the vertical gap.
	 */
	public FlowArrangement(HorizontalAlignment hAlign,
			VerticalAlignment vAlign, double hGap, double vGap) {
		this.horizontalAlignment = hAlign;
		this.verticalAlignment = vAlign;
		this.horizontalGap = hGap;
		this.verticalGap = vGap;
	}

	/**
	 * Adds a block to be managed by this instance. This method is usually
	 * called by the {@link BlockContainer}, you shouldn't need to call it
	 * directly.
	 * 
	 * @param block
	 *            the block.
	 * @param key
	 *            a key that controls the position of the block.
	 */
	public void add(Block block, Object key) {
		// since the flow layout is relatively straightforward,
		// no information needs to be recorded here
	}

	/**
	 * Calculates and sets the bounds of all the items in the specified
	 * container, subject to the given constraint. The <code>Graphics2D</code>
	 * can be used by some items (particularly items containing text) to
	 * calculate sizing parameters.
	 * 
	 * @param container
	 *            the container whose items are being arranged.
	 * @param constraint
	 *            the size constraint.
	 * @param g2
	 *            the graphics device.
	 * 
	 * @return The size of the container after arrangement of the contents.
	 */
	public Size2D arrange(BlockContainer container, Canvas g2,
			RectangleConstraint constraint) {

		LengthConstraintType w = constraint.getWidthConstraintType();
		LengthConstraintType h = constraint.getHeightConstraintType();
		if (w == LengthConstraintType.NONE) {
			if (h == LengthConstraintType.NONE) {
				return arrangeNN(container, g2);
			} else if (h == LengthConstraintType.FIXED) {
				return arrangeNF(container, g2, constraint);
			} else if (h == LengthConstraintType.RANGE) {
				throw new RuntimeException("Not implemented.");
			}
		} else if (w == LengthConstraintType.FIXED) {
			if (h == LengthConstraintType.NONE) {
				return arrangeFN(container, g2, constraint);
			} else if (h == LengthConstraintType.FIXED) {
				return arrangeFF(container, g2, constraint);
			} else if (h == LengthConstraintType.RANGE) {
				return arrangeFR(container, g2, constraint);
			}
		} else if (w == LengthConstraintType.RANGE) {
			if (h == LengthConstraintType.NONE) {
				return arrangeRN(container, g2, constraint);
			} else if (h == LengthConstraintType.FIXED) {
				return arrangeRF(container, g2, constraint);
			} else if (h == LengthConstraintType.RANGE) {
				return arrangeRR(container, g2, constraint);
			}
		}
		throw new RuntimeException("Unrecognised constraint type.");

	}

	/**
	 * Arranges the blocks in the container with a fixed width and no height
	 * constraint.
	 * 
	 * @param container
	 *            the container.
	 * @param constraint
	 *            the constraint.
	 * @param g2
	 *            the graphics device.
	 * 
	 * @return The size.
	 */
	protected Size2D arrangeFN(BlockContainer container, Canvas g2,
			RectangleConstraint constraint) {

		List blocks = container.getBlocks();
		double width = constraint.getWidth();

		double x = 0.0;
		double y = 0.0;
		double maxHeight = 0.0;
		List itemsInRow = new ArrayList();
		for (int i = 0; i < blocks.size(); i++) {
			Block block = (Block) blocks.get(i);
			Size2D size = block.arrange(g2, RectangleConstraint.NONE);
			if (x + size.width <= width) {
				itemsInRow.add(block);
				block.setBounds(new Rectangle2D.Double(x, y, size.width,
						size.height));
				x = x + size.width + this.horizontalGap;
				maxHeight = Math.max(maxHeight, size.height);
			} else {
				if (itemsInRow.isEmpty()) {
					// place in this row (truncated) anyway
					block.setBounds(new Rectangle2D.Double(x, y, Math.min(
							size.width, width - x), size.height));
					x = 0.0;
					y = y + size.height + this.verticalGap;
				} else {
					// start new row
					itemsInRow.clear();
					x = 0.0;
					y = y + maxHeight + this.verticalGap;
					maxHeight = size.height;
					block.setBounds(new Rectangle2D.Double(x, y, Math.min(
							size.width, width), size.height));
					x = size.width + this.horizontalGap;
					itemsInRow.add(block);
				}
			}
		}
		return new Size2D(constraint.getWidth(), y + maxHeight);
	}

	/**
	 * Arranges the blocks in the container with a fixed width and a range
	 * constraint on the height.
	 * 
	 * @param container
	 *            the container.
	 * @param constraint
	 *            the constraint.
	 * @param g2
	 *            the graphics device.
	 * 
	 * @return The size following the arrangement.
	 */
	protected Size2D arrangeFR(BlockContainer container, Canvas g2,
			RectangleConstraint constraint) {

		Size2D s = arrangeFN(container, g2, constraint);
		if (constraint.getHeightRange().contains(s.height)) {
			return s;
		} else {
			RectangleConstraint c = constraint.toFixedHeight(constraint
					.getHeightRange().constrain(s.getHeight()));
			return arrangeFF(container, g2, c);
		}
	}

	/**
	 * Arranges the blocks in the container with the overall height and width
	 * specified as fixed constraints.
	 * 
	 * @param container
	 *            the container.
	 * @param constraint
	 *            the constraint.
	 * @param g2
	 *            the graphics device.
	 * 
	 * @return The size following the arrangement.
	 */
	protected Size2D arrangeFF(BlockContainer container, Canvas g2,
			RectangleConstraint constraint) {

		// TODO: implement this properly
		return arrangeFN(container, g2, constraint);
	}

	/**
	 * Arranges the blocks with the overall width and height to fit within
	 * specified ranges.
	 * 
	 * @param container
	 *            the container.
	 * @param constraint
	 *            the constraint.
	 * @param g2
	 *            the graphics device.
	 * 
	 * @return The size after the arrangement.
	 */
	protected Size2D arrangeRR(BlockContainer container, Canvas g2,
			RectangleConstraint constraint) {

		// first arrange without constraints, and see if this fits within
		// the required ranges...
		Size2D s1 = arrangeNN(container, g2);
		if (constraint.getWidthRange().contains(s1.width)) {
			return s1; // TODO: we didn't check the height yet
		} else {
			RectangleConstraint c = constraint.toFixedWidth(constraint
					.getWidthRange().getUpperBound());
			return arrangeFR(container, g2, c);
		}
	}

	/**
	 * Arranges the blocks in the container with a range constraint on the width
	 * and a fixed height.
	 * 
	 * @param container
	 *            the container.
	 * @param constraint
	 *            the constraint.
	 * @param g2
	 *            the graphics device.
	 * 
	 * @return The size following the arrangement.
	 */
	protected Size2D arrangeRF(BlockContainer container, Canvas g2,
			RectangleConstraint constraint) {

		Size2D s = arrangeNF(container, g2, constraint);
		if (constraint.getWidthRange().contains(s.width)) {
			return s;
		} else {
			RectangleConstraint c = constraint.toFixedWidth(constraint
					.getWidthRange().constrain(s.getWidth()));
			return arrangeFF(container, g2, c);
		}
	}

	/**
	 * Arranges the block with a range constraint on the width, and no
	 * constraint on the height.
	 * 
	 * @param container
	 *            the container.
	 * @param constraint
	 *            the constraint.
	 * @param g2
	 *            the graphics device.
	 * 
	 * @return The size following the arrangement.
	 */
	protected Size2D arrangeRN(BlockContainer container, Canvas g2,
			RectangleConstraint constraint) {
		// first arrange without constraints, then see if the width fits
		// within the required range...if not, call arrangeFN() at max width
		Size2D s1 = arrangeNN(container, g2);
		if (constraint.getWidthRange().contains(s1.width)) {
			return s1;
		} else {
			RectangleConstraint c = constraint.toFixedWidth(constraint
					.getWidthRange().getUpperBound());
			return arrangeFN(container, g2, c);
		}
	}

	/**
	 * Arranges the blocks without any constraints. This puts all blocks into a
	 * single row.
	 * 
	 * @param container
	 *            the container.
	 * @param g2
	 *            the graphics device.
	 * 
	 * @return The size after the arrangement.
	 */
	protected Size2D arrangeNN(BlockContainer container, Canvas g2) {
		double x = 0.0;
		double width = 0.0;
		double maxHeight = 0.0;
		List blocks = container.getBlocks();
		int blockCount = blocks.size();
		if (blockCount > 0) {
			Size2D[] sizes = new Size2D[blocks.size()];
			for (int i = 0; i < blocks.size(); i++) {
				Block block = (Block) blocks.get(i);
				sizes[i] = block.arrange(g2, RectangleConstraint.NONE);
				width = width + sizes[i].getWidth();
				maxHeight = Math.max(sizes[i].height, maxHeight);
				block.setBounds(new Rectangle2D.Double(x, 0.0, sizes[i].width,
						sizes[i].height));
				x = x + sizes[i].width + this.horizontalGap;
			}
			if (blockCount > 1) {
				width = width + this.horizontalGap * (blockCount - 1);
			}
			if (this.verticalAlignment != VerticalAlignment.TOP) {
				for (int i = 0; i < blocks.size(); i++) {
					// Block b = (Block) blocks.get(i);
					if (this.verticalAlignment == VerticalAlignment.CENTER) {
						// TODO: shift block down by half
					} else if (this.verticalAlignment == VerticalAlignment.BOTTOM) {
						// TODO: shift block down to bottom
					}
				}
			}
		}
		return new Size2D(width, maxHeight);
	}

	/**
	 * Arranges the blocks with no width constraint and a fixed height
	 * constraint. This puts all blocks into a single row.
	 * 
	 * @param container
	 *            the container.
	 * @param constraint
	 *            the constraint.
	 * @param g2
	 *            the graphics device.
	 * 
	 * @return The size after the arrangement.
	 */
	protected Size2D arrangeNF(BlockContainer container, Canvas g2,
			RectangleConstraint constraint) {
		// TODO: for now we are ignoring the height constraint
		return arrangeNN(container, g2);
	}

	/**
	 * Clears any cached information.
	 */
	public void clear() {
		// no action required.
	}

	/**
	 * Tests this instance for equality with an arbitrary object.
	 * 
	 * @param obj
	 *            the object (<code>null</code> permitted).
	 * 
	 * @return A boolean.
	 */
	public boolean equals(Object obj) {
		if (obj == this) {
			return true;
		}
		if (!(obj instanceof FlowArrangement)) {
			return false;
		}
		FlowArrangement that = (FlowArrangement) obj;
		if (this.horizontalAlignment != that.horizontalAlignment) {
			return false;
		}
		if (this.verticalAlignment != that.verticalAlignment) {
			return false;
		}
		if (this.horizontalGap != that.horizontalGap) {
			return false;
		}
		if (this.verticalGap != that.verticalGap) {
			return false;
		}
		return true;
	}

}
